Guidelines for preventing the transmission of tuberculosis in health-care settings, with special focus on HIV-related issues.

The transmission of tuberculosis is a recognized risk in health-care settings. Several recent outbreaks of tuberculosis in health-care settings, including outbreaks involving multidrug-resistant strains of Mycobacterium tuberculosis, have heightened concern about nosocomial transmission. In addition, increases in tuberculosis cases in many areas are related to the high risk of tuberculosis among persons infected with the human immunodeficiency virus (HIV). Transmission of tuberculosis to persons with HIV infection is of particular concern because they are at high risk of developing active tuberculosis if infected. Health-care workers should be particularly alert to the need for preventing tuberculosis transmission in settings in which persons with HIV infection receive care, especially settings in which cough-inducing procedures (e.g., sputum induction and aerosolized pentamidine [AP] treatments) are being performed. Transmission is most likely to occur from patients with unrecognized pulmonary or laryngeal tuberculosis who are not on effective antituberculosis therapy and have not been placed in tuberculosis (acid-fast bacilli [AFB]) isolation. Health-care facilities in which persons at high risk for tuberculosis work or receive care should periodically review their tuberculosis policies and procedures, and determine the actions necessary to minimize the risk of tuberculosis transmission in their particular settings. The prevention of tuberculosis transmission in health-care settings requires that all of the following basic approaches be used: a) prevention of the generation of infectious airborne particles (droplet nuclei) by early identification and treatment of persons with tuberculous infection and active tuberculosis, b) prevention of the spread of infectious droplet nuclei into the general air circulation by applying source-control methods, c) reduction of the number of infectious droplet nuclei in air contaminated with them, and d) surveillance of health-care-facility personnel for tuberculosis and tuberculous infection. Experience has shown that when inadequate attention is given to any of these approaches, the probability of tuberculosis transmission is increased. Specific actions to reduce the risk of tuberculosis transmission should include a) screening patients for active tuberculosis and tuberculous infection, b) providing rapid diagnostic services, c) prescribing appropriate curative and preventive therapy, d) maintaining physical measures to reduce microbial contamination of the air, e) providing isolation rooms for persons with, or suspected of having, infectious tuberculosis, f) screening health-care-facility personnel for tuberculous infection and tuberculosis, and g) promptly investigating and controlling outbreaks. Although completely eliminating the risk of tuberculosis transmission in all health-care settings may be impossible, adhering to these guidelines should minimize the risk to persons in these settings.